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<TITLE>[Chapter 30] 30.6 java.util.Enumeration (JDK 1.0)</TITLE>
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<h2 CLASS=sect1><A CLASS="TITLE" NAME="JNUT2-CH-30-SECT-6">30.6 java.util.Enumeration (JDK 1.0)</A></h2>

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<h3 CLASS=sect2><A CLASS="TITLE" NAME="JNUT2-CH-30-SECT-6.1"></A></h3>
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<P CLASS=para>
This interface defines the methods necessary to enumerate,
or iterate through, a set of values, such as the set of
values contained in a hashtable or binary tree. It is
particularly useful for data structures, like hashtables,
for which elements cannot simply be looked up by index, as
they can in arrays. An <tt CLASS=literal>Enumeration</tt> is usually not
instantiated directly, but instead is created by the object
that is to have its values enumerated. A number of classes,
such as <tt CLASS=literal>Vector</tt> and <tt CLASS=literal>Hashtable</tt>, have methods
that return <tt CLASS=literal>Enumeration</tt> objects.

<P CLASS=para>
To use an <tt CLASS=literal>Enumeration</tt> object, you use its two
methods in a loop: <tt CLASS=literal>hasMoreElements()</tt> returns
<tt CLASS=literal>true</tt> if there are more values to be enumerated, and
can be used to determine whether a loop should continue.
Within a loop, a call to <tt CLASS=literal>nextElement()</tt> returns a
value from the enumeration. An <tt CLASS=literal>Enumeration</tt> makes no
guarantees about the order in which the values are returned.
The values in an <tt CLASS=literal>Enumeration</tt> may be iterated through
only once--there is no way to reset it to the beginning.

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<PRE>
public abstract interface <tt CLASS=literal>Enumeration</tt> {
    // <tt CLASS=literal>Public Instance Methods</tt>
            public abstract boolean <tt CLASS=literal>hasMoreElements</tt>();
            public abstract Object <tt CLASS=literal>nextElement</tt>();
}
</PRE>
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<h3 CLASS=sect2><A CLASS="TITLE" NAME="JNUT2-CH-30-SECT-6.2">Implemented By:</A></h3>

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StringTokenizer

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SequenceInputStream()

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AppletContext.getApplets(), 
Dictionary.elements(), 
Dictionary.keys(), 
FeatureDescriptor.attributeNames(), 
Hashtable.elements(), 
Hashtable.keys(), 
ListResourceBundle.getKeys(), 
MenuBar.shortcuts(), 
Properties.propertyNames(), 
PropertyResourceBundle.getKeys(), 
ResourceBundle.getKeys(), 
Vector.elements(), 
ZipFile.entries()

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